A variety of cleaning implements have been proposed for cleaning the surface of furniture, walls, and floors of houses, automotive interior trim, and the like. Amongst them is a cleaning tool having a handle and a head to which a cleaning sheet made of nonwoven fabric, etc. is attached.
The conventionally employed cleaning sheets are capable of entrapping hair, lint, soil or like dust and debris by entanglement in the fibers of nonwoven fabric but have difficulties in holding by entanglement all the dust and debris, from fine dust to solid particles of about 1 mm or greater in size, such as sand, pebbles, food crumbs, rice grains, and sesame seeds. Such large solid particles cannot be removed but with a dustpan or a vacuum cleaner.
Hence, a cleaning sheet or cloth having tacky parts disposed in the wiping portion thereof has been proposed in JP-A-9-164110 and JP-A-9-224895, which is capable of catching those dust particles that cannot be entangled in fibers by its tacky parts.
When the proposed cleaning sheet is used in a usual manner of cleaning, that is, when the cleaning sheet is slid on a surface to be cleaned, the dust and debris are not trapped onto the tacky parts. Therefore, a user must aim at the debris and press the cleaning sheet onto the debris with a certain force so that the debris may be trapped by the sticky parts. Even when a user presses a cleaning tool to catch debris, however, the dust trapping efficiency is low because the tacky parts are disposed in parts. Moreover, if large ones of various kinds of dust that have not been entangled in the fibers, i.e., large diameter dust particles or thick dust particles, are the first to be trapped by the tacky parts, the wiping part of the cleaning sheet is hindered by the large dust particles from coming into intimate contact with the surface to be cleaned. It can follow that the cleaning sheet fails to catch up not only the other kinds of dust that have not been entangled but also the dust that should otherwise be entangled in the fibers.
JP-A-2000-93373 proposes a cleaning sheet having a plurality of recesses along the edges (borders) between the wiping portion and the fixing portions so that relatively large dust particles may be led to the central region of the wiping portion through the recesses.
However, the borders contain straight linear parts along the length direction of a cleaning mop between every adjacent recesses. When the cleaning sheet is used in an ordinary sweeping operation (for example, sliding the wiping portion on a floor, etc.), the straight linear parts block the approach of dust. As a result, the cleaning sheet is incapable of catching dust sufficiently.
Merely having the recesses, the cleaning sheet has low capability of catching and holding the above-mentioned relatively large solid dust and is therefore incapable of trapping such dust sufficiently.
JP-A-10-5163 discloses a disposable wiping material which is substantially rectangle in its plan view, is made of fiber aggregates different in fiber density, and has a first surface and a second surface parallel to each other. The first surface is substantially flat. The cleaning sheet consists of side portions with a certain width and a high fiber density, each of which is along each of opposing parallel edges of the material, and a middle portion with a low fiber density between the side portions. The second surface is relatively low in the side portions and relatively high in the middle portion.
While the wiping material can keep the side portions a little distance away from the floor, etc., dust particles having a different size (height) from that distance are not brought into contact with the side portions, and the wiping material shows no collecting and trapping performance for the dust particles. When the wiping material is used in a usual sweeping operation (for example, sliding the wiping portion on a floor, etc.), it has difficulty in catching relatively large solid dust particles of the above stated size.
An object of the present invention is to provide a cleaning sheet with which relatively large solid dust particles as well as fine dust particles can be trapped without fail in a usual sweeping operation on an object to be cleaned.